There is increasing interest in using terahertz (THz) radiation for applications in various fields including medical imaging, security, scientific investigations, imaging, communications, and manufacturing. Terahertz radiation refers to electromagnetic waves in the terahertz frequency range. The terahertz frequency range as referred to herein generally identifies those frequencies lying nominally between approximately 200 gigahertz and approximately 3 terahertz.
Systems that emit terahertz radiation could be effective medical diagnostic and research tools since, unlike X-rays, terahertz radiation generally will not damage biological tissues due to its non-ionizing nature. Terahertz radiation can also be used at airports and other areas for the detection of concealed weapons as it can penetrate fabrics and plastics. Terahertz radiation could be used in spectroscopic investigations in the fields of chemistry and biochemistry among others. Such radiation could be used in telecommunications above altitudes where water vapor in the air would cause signal absorption. Since plastics and cardboard are transparent at terahertz frequencies, such radiation has been proposed for inspecting packaged goods for process and quality control in some manufacturing environments.
Systems that emit and receive electromagnetic waves at terahertz frequencies have limited availability due to alignment and precision difficulties of machined waveguides and interconnect losses associated with attaching active electronic circuitry to terahertz waveguide components. The manufacturing of these systems is cost restrictive, and manufacturing volume is very low.